How home solar and battery storage kept the lights on in South Australia

Home solar and battery storage systems have been credited with keeping the lights on during a period of record minimum demand in South Australia in October last year, in an Australian Energy Market Operator report on virtual power plants released this week.

In a statement accompanying its latest VPP Knowledge Sharing Report, AEMO says consumer solar and batteries came to the rescue of the South Australian grid on October 11, adding roughly 5MW to operational demand at a time when it had hit dangerous record lows.

“Our third knowledge sharing report showed that VPPs assisted in elevating the South Australian operational demand by approximately 5MW during the record minimum demand period on 11 October 2020, which reduced the severity of the event,” said the AEMO’s chief member services officer, Violette Mouchaileh.

The rapid decline of minimum operational (grid) demand, driven by the increasing contributions of distributed solar generation to meet consumer demand in the daytime, was highlighted as one of the key challenges to all areas of the National Electricity Market in AEMO’s 2020 Electricity Statement of Opportunities.

By 2025, the ESOO said, all regions were expected to experience minimum operational demand in the daytime; a trend, AEMO warned, that was creating near-term operational and planning challenges for sustaining a reliable and secure grid, first and foremost in South Australia.

The ESOO also noted, however, that innovative solutions to this problem could include providers/aggregators of distributed energy resources – VPPs – offering services such as increased PV controllability, load flexibility, storage, and load shifting.

The South Australia example bears out this theory.

Beyond this key achievement, the February 2021 AEMO report documents the performance of aggregated and intelligently coordinated consumer-owned distributed energy resources (DERs) – currently mostly residential solar and battery storage – on the National Electricity Market.

AEMO, with funding from the Australian Renewable Energy Agency, currently has a total of seven VPP participants taking part in its VPP Demonstrations program, with more than 5,000 consumers located in multiple states with varying DER technologies.

AEMO noted in its report that while the VPP industry was becoming more sophisticated – as reflected in dynamic switching controllers, response to minimum demand and diversified consumer offerings – it was still very much a work in progress, particularly from the grid services side of the equation.

“We’ve seen that VPPs prioritise fleet availability for Frequency Control Ancillary Services (FCAS) markets over other value streams, such as energy arbitrage. This makes accurately forecasting behaviour as VPPs scale more complex,” Mouchaileh said.

“Therefore, ongoing collaboration with industry and development of operational visibility, forecast-ability and dispatchability of VPPs will be critical to ensuring efficient integration into the power system,” she said.

On the consumer side of the equation, the report said early insights had shown that participants in the demonstrations VPPS were motivated by a variety of factors, including further reducing their energy bills; accessing government subsidies/discounts on hardware; and having a backup energy supply.

Others were motivated by being a part of the latest technology and pioneering in energy solutions, the report said, as well as by being able to maximise the use of their self-generation assets, or by contributing to the greater good by helping to avoid outages.

“Positive expectations mostly translate into high levels of satisfaction; keeping consumers informed about financial, environmental and societal benefits is encouraged to maintain high levels of satisfaction,” Mouchaileh said.

A comprehensive Consumer Insights Report will be published by AEMO in July.